Im in the process of upgrading our ESX 4.0 hosts to ESXi 5. Best practices state to detach SAN luns when upgrading. Some forums I have read said this was mainly for 3.5 version. Is it really necessary to disconnect before proceeding? Using update manager for upgrade process.
if your storage system is supported by the new ESXi version without the need to first upgrade firmware or change some settings, then there's no real need to detach the storage. I haven't done this since v4.0.
